Electrode for electrolytic cells



- Mam 4, 11930.

E. F. LUNDEEN ELECTRODE FOR ELECTRQLYTIC CELLS Filed Jan. 31,- 1927 IE 12 672 Zfm? 0&6

Patented Mar. 4, 1930 UNITEDv STATES PATENT OFFICE ERNEST F. LUNDEEN, OF CLEVELAND HEIGHTS, OHIO, ASSIGNOR T WILLARD STOR- AGE BATTERY COMPANY, OF CLEVELAND, OHIO, A COBPCRATION OF WEST VIB- GDIIA ELECTRODE FOE ELECTROLYTIC CELLS Application filed January 31, 1927. Serial No. 164,663,

This invention relates to electrolytic cells and particularly to an improved electrode for use in cells employed as rectifiers.

Considerable effort has been expended towards increasing the life of electrolytic cells used as rectifiers since deterioration of the electrolyte and of the electrodes is commonly quite rapid. Working upon the problem of reducing the deterioration of a film-forming aluminum electrode, Mr. Campbell C. Carenter has discovered and covered in U. S. etters Patent N 0. 1,600,397, issued Septem= improvement over those previously used.

The electrolyte described in the said patent contains a citrate such as citric acid.

I have found that electrolytes of this character, while improving the efficiency and life of the cell, gradually attack chemically the non-film-forming electrode which is ordinarily composed of lead, and while this chemical action is not rapid, nevertheiess it does, in the course of time, become sufficient to hasten the decomposition of the citric acid or other material for the same purpose during idle periods and to cause the metal of the electrode to be carried over electrolytically onto the film -forming electrode. Where the material of the non-film-formin electrode is lead, the coating so formed on t e aluminum electrode during the periods when the rectifier is idle interferes with the functioning of the rectifier. For instance, I have found that after such periods of idleness an appreciable length of time is reryuired, sometimes as much as ve minutes, be ore rectification actually begins. When iron or steel is employed instead of lead, the chemical action referred to is less pronounced. With iron or steel of ordinary character, however, another difficulty is encountered namely, the formation of an ex losive gas during periods of rectification, a azard which is great enough to make lead preferable to iron for commercial use.

Having come to a realization of the above facts, I made the discovery that if an alloy of iron with a considerable proportion of chromium be employed as the material for the nonfilm-forming electrode no explosive gas 50 is given off, and, furthermore, the electrode her 21, 1926, an electrolyte which Was a-great is not attacked by the electrolyte when the cell is idle and the decomposition of the electrolyte is accordingly much slower, all of which results in greatly increased efficiency and longer life of the cell. Steel rather than iron may be employed, but iron makes the better electrode, in other words, the carbon content of the alloy should be low for best results. The formula which I prefer at the present time is substantially as follows:

Iron 86.85 parts Carbon .15 parts, and Chromium "13 parts, by weight.

Although my improved electrode is particularly advantageous when used with an electrolyte such as that disclosed in the Carpenter patent above referred to, it does, however, resist harmful chemical action of any kind as distinguished from electrolytic action, and, therefore, has a quite general application.

In the accompanying drawing wherein I have shown one of the numerous forms of cells which'may be employed advantageously, the single figure is a sectional view, and in it 10 represents the jar, 11 the cover therefor, 12- the electrodes which are supported by the cover, and 13 represents the electrolyte.

Changes may be made in the ingredients employed and in the proportions of the ingredients, and I therefore aim in my claims to cover all modifications which do not involve a departure from the spirit and scope of my invention.

Having described my invention, I claim:

1. In an electrolytic cell, a suitable electrolyte, a film-forming electrode, and a ferrous electrode containing substantially thirteen per cent by weight of chromium.

2. In an electrolytic cell, a suitable electrolyte, a film-forming electrode, and a ferrous electrode containing more than ten per cent by weight of chromium.

3. In an electrolytic cell, a suitable electrolyte, a film-forming electrode, and a ferrous electrode containing a relatively small percentage of carbon and more than ten per cent by weight of chromium.

4. In an electrolytic cell, an electrolyte which will combine under electrolytic action with a film-forming electrode and containing a substance to retard coagulation of the salt resultin from the combination of the electro- 5 lyte wit the film-forming electrode, a filmforming electrode, and an electrode composed of an iron chromium alloy.

5. In an electrolytic cell, an electrolyte containin citric acid, a film-forming electrode, 10 and a errous electrode containing more than ten per cent by weight of chromium.

In testimony whereof, I hereunto afiix my signature. I

ERNEST F. LUNDEEN. 

